Warrnambool Sewage Treatment Plant Upgrade

Wannon Water is currently planning a project to upgrade the existing Warrnambool Sewage Treatment Plant to meet the needs of housing and economic growth in the region. The aim is to ensure the plant has sufficient capacity for a projected increase in sewage volumes while continuing our responsibility to protect the environment.

The project, estimated to cost between $30 and $40 million, will be the largest ever single project undertaken by Wannon Water. It will ensure the plant has sufficient capacity for a projected increase in sewage volumes while continuing to protect the environment.

Two new intermittently decanted extended aeration (IDEA) tanks are planned for construction on the northern side of the facility to supplement the four existing tanks.

A Stakeholder Reference Group, consisting of residents, customers, and representatives of key interest groups and major customers, was established to help determine the preferred upgrade option for the community and the region as a whole.

The preferred option, based on balancing capital and operational costs, technical considerations, and environmental and social impacts, was endorsed by the Wannon Water Board in May. The IDEA process has been in use at the plant for more than 20 years and is a robust and proven technology, both at the site and throughout the water industry.

The project's design and approvals process is scheduled to begin later this year with construction expected to start in 2019 and take around two years to complete.

The need for an upgrade

The region’s importance as a food industry hub means that demands on the Warrnambool Sewage Treatment Plant are much higher than would normally be expected based purely on population levels. While it is successfully meeting current demands, the plant is operating near capacity, treating around 15 million litres of sewage each day.

Residential and industrial development in Warrnambool is also expected to grow in the coming years. For example, the plant currently services nearly 15,000 houses, but this figure is expected to increase by more than 80 per cent to 25,000 properties in the next 50 years. Upgrading this plant will ensure we are doing all we can to protect and enhance the local environment and support the economic growth and prosperity of the Great South Coast region.

Upgrade options

After a rigorous analysis of potential options for the future of sewage treatment in Warrnambool, engineering consultants provided a short list of options for the preferred approach of upgrading the existing Warrnambool Sewage Treatment Plant to increase its capacity by around 40 per cent.

The preferred option, endorsed by the Wannon Water Board in May, is the construction of two new intermittently decanted extended aeration (IDEA) tanks. The plan is to place them on the northern side of the facility to supplement the four existing IDEA tanks.

A Stakeholder Reference Group, consisting of residents, customers and representatives of key interest groups and major customers, was established to help decide the preferred upgrade option for the community and the region as a whole.

The IDEA process has been in use at the plant for more than 20 years and is a robust and proven technology, both at the site and throughout the water industry.

Community input

Wannon Water engaged with a Stakeholder Reference Group for the project in March and April 2017 to help decide on the best upgrade option based on balancing capital and operational costs, technical considerations, and environmental and social impacts.

Residents and representatives of recreational and environmental groups, aboriginal people, the EPA and the Department of Environment, Land, Water and Planning, members of our Community Advisory Committee and local business and industry were invited to participate through an expression of interest process. The group met to help determine the criteria (and weightings) that were used to assess the shortlisted options presented to the board for a final decision.

Wannon Water has also consulted with nearby residents, local businesses, industries, recreational users and environmental groups about the project. This will continue throughout the entire design and construction stages.

We also briefed stakeholders, including government agencies, local government, regional groups, local Members of Parliament and our Community Advisory Committee.